Technical Field
The present disclosure relates to a seat cushion extension apparatus for a vehicle seat. More particularly, it relates to a seat cushion extension apparatus for a vehicle seat, which has an improved structure capable of conveniently moving a portion of a front section of a seat cushion in a forward direction, to adjust the seat cushion to the contour of an occupant's body.
Background Art
Generally, a vehicle seat includes a seat cushion for supporting the back of the lower body of an occupant, to provide comfortable sitting to the occupant when the occupant is seated on the seat cushion, a seatback for supporting the upper body of the occupant, and a headrest for supporting the head and neck portions of the occupant.
Meanwhile, the seat cushion has a fixed size and, as such, may be incapable of providing optimal convenience to the occupant in that the occupant may have various personal body characteristics.
For example, in the case of a driver who has short legs, there may be a problem in that the legs of the driver cannot reach a pedal or driving may be inconvenient even when the seat cushion is moved forwards.
In order to solve such a problem, there have been proposed a cushion extension structure in which a portion of a front section of a seat is formed as a separate element, and is mounted to the seat to be movable with respect to the seat, using a power motor and a lead screw, and a locking structure for locking the cushion extension structure in a manually adjustable manner, using a gear member and a stopper.
An example of the structure capable of moving a portion of the front section of the seat with respect to the seat is disclosed in Korean Registered Patent No. 10-1470185 (registered on Dec. 1, 2014). This patent discloses a seat cushion extension pad device for a vehicle seat including a lower support frame fixed, at a lower portion thereof to a vehicle frame, a rotating arm pivotally coupled, at one end thereof, to a rear portion of the lower support frame at one side of the lower support frame while being coupled, at the other end thereof, to a lower portion of a seat cushion extension pad, and a hinge bracket pivotally coupled to a front portion of the lower support frame at one side of the lower support frame, to guide rotation of the seat cushion extension pad when the seat cushion extension pad moves.
As another example, a seat cushion extension apparatus is disclosed in Korean Registered Patent No. 10-1506351 (registered on Mar. 20, 2015). As shown in FIG. 1, the disclosed seat cushion extension apparatus includes an actuating bracket 10 pivotally coupled to a cushion frame 1, to be moved forwards by load of a seat cushion occupant, an extension frame 20 connected to the cushion frame 1, to be movable in a forward direction from a front surface of the cushion frame 1 such that the extension frame 10 protrudes from the cushion frame 1, a power transmission unit 30 installed to connect the actuating bracket 10 and the extension frame 20, and to provide force to move the extension frame 20 in the forward direction when the power transmission unit 30 moves forwards in link with the actuating bracket 10 and force to return the extension frame 20 in a rearward direction, a locking unit 40 provided at the cushion frame 1 and extension frame 20, to lock forward and rearward movement of the extension frame 20, and a lever unit 50 provided at the cushion frame 1, to be connected to the locking unit 40 such that the lever unit 50 operates when depressed in a one touch fashion, to operate the locking unit 40.
In the above-mentioned conventional cushion extension structure, however, there are problems of increase in cost, increase in weight, and motor noise due to use of the power motor. Meanwhile, in the conventional manual extension apparatus, an improvement in structure in consideration of marketability of the extension apparatus is required because noise is generated due to excessive clearances among constituent elements caused by low accuracy of operation.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.